# @author:leacoder
# @des:   和固定利用差值diff 两数之和 
class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        for i in range(len(nums)-1):
            diff = target - nums[i]
            if diff in nums[i+1:]: 
                return [i,nums[i+1:].index(diff)+i+1]
        return []